<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var s = new Set();
        //添加和删除
        s.add(100);
        s.add(200);
        s.delete(100);
        //判断是否存在set中
        s.has(100);
        //清空set
        s.clear;

    </script>
</body>
</html>